Syringomyelia (SM) is a rare condition of the spinal cord that is seen in 8.4 out of 100,000. This condition occurs when the cerebrospinal fluid (CSF) forms cavities in the spine. This cavity is called syrinx.

 

Without treatment, the length and width of the syrinx can increase over time. The presences of these cysts stretching and putting pressure on the nerve fibres inside the spinal cord. This damage can cause a variety of symptoms and pain. These depend on the location of the syrinx in the spine.  

 

The most frequent cause of SM is associated with Chiari Malformation. The herniation of the cerebellum causes a blockage of the CSF. Approximately 30-50% of people with Chiari Malformation develop a syrinx. There are still only theories as to why a syrinx develops. This type of syrinx is called a communicating syringomyelia.

 

The second major form of syringomyelia is called acquired or non-communicating syringomyelia. Acquired syringomyelia can be caused by issues such as spinal cord injury, tumours, tethered cord etc.  

There is also no consensus on the difference between a dilated central canal and syringomyelia. Debate ranges on the size being the factor to consider.